In many network systems, it is desirable to add a cryptographic element to provide secure communications between endpoints. To provide security, the communications are encrypted on the transmitting end and decrypted at the receiving end using an encryption algorithm and corresponding key for the algorithm. The overall system contains “Red” and “Black” Networks. The Red Network is a secure network, for example a local area network (LAN), in which sensitive information is transmitted between trusted devices. Within the Red Network, messages are transmitted without encryption. The Black Network, however, is an unsecure network, such as the internet. Sensitive information from the Red Network is encrypted prior to being transmitted through the Black Network. Encrypted messages from the Red Network traverse the Black Network to reach an end device in either the Black Network or a different Red Network, in either of which they are decrypted. The Red-Black separation between the Red and Black Networks may occur in a microprocessor. One standard available for applying encryption to IP messages is called IPSec. The Red-Black separation in such an implementation is consequently referred to as an IPSec gateway.
Different entities have different security needs. For example, the security needs of a commercial vendor may be different from that of a government agency. Entities that have higher security requirements with regards to Red-Black separation and fault tolerance (i.e., tolerance to keys or unprotected data being accidently provided to the Black Network) in the past have had to use expensive, custom-built systems to provide the security as the requirements have not been able to be met with an off-the-shelf IPSec implementation. It is desirable to use commercial IPSec implementations while being able to provide a high level of security.
One of skill in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of the embodiments described.